Elucidation of gene expression in living matters is the most fundamental issue in applied sciences including, from unraveling an onset mechanism of disorders and development of new medical drugs, to food engineering. It is known that many genes are involved even in a certain phenomenon and a complicated network is formed among these genes.
The network is formed chronologically in three-dimensional space through transmission of stimuli caused by the release of a chemical substance to adjacent tissues, rather than being found locally in a single tissue.
On the other hand, experimentally observed data are discrete ones indicating frequency of expression of genes in each cell in each tissue at a certain instance in time.
Conventionally, analysis of expression profiles in living matters measures frequency of substances expressed (the number of molecules expressed) in isolated cell or tissue samples and the measurements are used as individual data or two-dimensional tabular data. Analytical systems used therefore can only graph out separately chronological changes of a given tissue or a given gene to observe the expression phenomenon as a map in the space obtained by scaling down coordinate dimensions.
With such analytical systems or methods, there is no way of adding in information indicative of proximity of cells or tissues. Even in the case where a gene A discovered in a cell causes expression of a gene B in an adjacent tissue, they are correlated just as one among others in the data and it is very difficult to determine an association therebetween.
More specifically, it is very difficult to elucidate a mechanism of coordinated expression directly from raw data in an analytical procedure that does not add in effects of any factors such as spatial and proximity information and that does not use any visualization technique evoking imaginations of an observer on a three-dimensional image. An approach that covers these shortcomings includes an in vivo staining experiment technique to observe a real organism directly rather than through analysis of data.
This is an approach to hybridize DNA of a gene to be analyzed with a directly labeled complementary DNA to visualize a frequency of expression based on the intensity of the label, which allows three-dimensional observation of how an expression proceeds in a living matter by changing viewpoints.
However, the above-mentioned in vivo staining experiment technique requires separate experiments for a single expression DNA or individual pairs of expression DNAs to be detected. In addition, suitable organisms for the staining experiment are limited to primitive translucent ones such as nematodes and Tardigrada of which label can be observed with a transmission light source. The technique cannot be applied to analysis of expression information on higher organisms including human. Thus, the problem exists that it is unable to elucidate a network mechanism of gene expression in the higher organisms.
The present invention is made with respect to problems in the prior art. An object thereof is to provide a method and a system for use in displaying an expression phenomenon in a living matter that are capable of displaying (printing), in a format directly appealing to the eyes or sense of a researcher, information indicative of gene expression occurring with time to assist the researcher with easy elucidation of a gene network mechanism.